Hormonal pollution of the environment, by compounds such as the potent 17b-estradiol, has been implicated in human and wildlife health problems. However, little is known regarding the environmental impact of hormones originating from animals. Such knowledge is timely.

Current animal waste regulations are driven solely by concerns about nutrients (notably P and N), pathogens, and organic matter, with no consideration given to the impact of these regulations on environmental estrogen loads.

Previous work examining livestock estrogen discharges has focused on poultry waste; little has been reported regarding the potentially large environmental loadings of estrogen from dairy operations. To address the gap in knowledge, this work has four objectives.

Fourth, determine the fate of 17b-estradiol in dry stacks, lagoons, high-rate anaerobic digesters, and soil. Specifically, use radiolabeled estrogens in lab studies to establish the extent to which microbes in these systems can mineralize estrogens.